Often referred to as the profile
or series, the aspect ratio of a tire is determined by dividing
a tire's section height by its section width when the tire
is:
Inflated to maximum air pressure, Mounted on the approved
measuring rim, and Under no load.

The lower aspect ratio responds to
lateral force more effectively than a tire with a higher aspect
ratio.

The aspect ratio affects steering stability. Generally, the
shorter the sidewall, or the lower the aspect ratio, the less
time it takes to transmit the steering input from the wheel
to the tread. The result is quicker steering response.

Aspect ratio also affects the tread contact patch. As a rule,
a low profile tire produces a wider tread contact patch. This
wider tread contact patch creates a stiffer footprint that reduces
distortion and provides improved cornering traction. Aspect
ratio also impacts ride. A low profile tire usually has a stiffer
ride than the standard aspect ratio of 75 or more.